Ubuntu-MATE is my distro for work and basically any situation in which I need a computer that's compatible with the most amount of stuff. One of the things I've noticed is that it's the only distro I run that seems to use the KeePassX 2.x versions instead of the 0.4 versions. I think 0.4 actually runs a bit better and was wondering if there's a way to make MATE use 0.4 instead.Thanks!

Well KeePassX 0.4 version can start in the tray and minimize to the tray without fully closing, as well as lock when minimized, which is something to the 2.x version cannot do. It's mainly that each of my other distros (Arch, Tails, etc) uses the 0.4 version, and MATE is the lone 2.x user, which means I have to do a bunch of witchcraft to get the files readable by 0.4 to work on 2.x, and 2.x files aren't readable on 0.4

I just checked keepassx on my machine (v2.0.2) and it has all those features, which can be enabled in settings. I believe that Tails is based on Debian. Debian has v2 of keepassx if you add the backports repository. Arch also has keepassx v2 available, the package name is keepassx2.

BOOM!You Sir, are the man. And quite possibly psychic. Final question: I assume the only way to update the program is to recompile whenever there's a new version? Or as there a convenient, Arch Linux style way of doing so?

Not psychic, hehe. I just decided to fully compile it myself and bumped into that error.

As for updating, I think 0.4.4 was the end of that branch, no? There won't be more upgrades to that version. The main development branch now is KeePassX 2.X and you won't need to compile for that, because as you know, it's what Ubuntu-MATE is already offering through the repositories. 0.4.4 is however a very stable version. It can serve you for years.

One final note:

I noticed the makefile doesn't do a standard installation. It should create a folder for you inside $HOME/bin. Instead it considers that the root folder for the installation. So you end up with a $HOME/bin/bin and a $HOME/bin/share folder. That is ugly!

Since you can already fully compile it, I advise you to delete $HOME/bin/bin and $HOME/bin/share and start over. Only this time, you are going to give it the folder name, like so:

First clean all the object files that were created during the build. So, trom inside Downloads/keepass:

$ make clean

Then build again, time time giving it the folder name (manually create it first):

$ qmake-qt4 PREFIX=$HOME/bin/keepass/
$ make
$ make install

And this time it will be neatly installed into ~/bin/keepass

EDIT 2:Oh, and don't forget to mark the thread as solved, so that any future reader with a similar problem, knows there is a solution.

That's one of the advantages of installing to your home folder. You can just back your new keepassx directory (and the database, of course) and copy into the new Tails installation. No need to recompile anymore.